Safety attachment for locks.



F. E. KEIZER.

SAFETY ATTACHMENT FOR LOCKS.

APPLICATION FILED APR. 4. I918:

1,277,22 Patented Aug. 27, l9l8.

Fig.1. Fig. Z:

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Faun KEIZER, orLos ANeELEs, CALIFORNIA.

SAFETY ATTACHMENT on LOCKS. ")1;

' Application filed a riu, 1918. se ial 110,226,726.

'To all whom it may concern: 1 7

Be it known that I, FRED E. KEI a citizen of the UnitedfStates,residing at Los Angeles, 'in the county of Los Angeles and State of California, have invented new and useful Improvements in Safety Attachments for Locks, of which the following is a specification. I

My invention relates to looks, my object being to make a safety attachment which may be readily applied to an ordinary door lock to reduce the liability of the lock being picked from the outside, and my invention consists in the novel features herein shown, described and claimed.

Figure 1 is a fragmentary perspective of the lock and a portion of the door as seen from the inside.

Fig. 2 is a view analogous to Fig. 1, the parts being shown as seen from the outside of the door.

Fig. 3 is an enlarged fragmentary edge view of the door in the vicinity of the lock, parts of the door and lock being broken away and shown in section.

Fig. 4 is a side and end elevation of the attachment cylinder removed from the door.

The mortise lock 1 is mounted in the door- 2 in the usual way and has an escutcheon plate 3 and a knob 1 on the inside of the.

door and an escutcheon plate 5 and a knob 6 on the outside of the door. In applying my safety attachment, I take the regular key 7 and cut a tongue groove 8 across its inner end. The attachment cylinder 9 has an attaching flange 10 extending outwardly around its outer end and screw holes '11 through flange 10. I remove the escutcheon plate 5, bore a cylinder chamber 12 from the outer face of the door in line with the key 7, place the cylinder 9 with the flange 10 against the inner face of the escutcheon, place the key hole plate 13 against the escutcheon plate 5 and insert the screws 14; through the key hole plate 13, through the escutcheon plate 5, and through the holes 11 in the flange and apply the nuts, and then place the escutcheon plate 5 in position upon the door. The connecting plate 15 is mounted in the inner end of the cylinder 9 to be rotated by the rotation of the cylinder key 16. A tongue 17 extends from the inner face of the connecting plate 15 to fit in the groove 8 in the key 7. The casing 18 of the cylin- I der 9 is rigidly fixed relative to the connecting plate 15' and a tooth 19 extends from the casing and engages shoulders 20 and 21 upon the connecting'plate 15,,so asto limit the'rotation or oscillation back and forth of the plate. V V V The periphery of the plate 15 is cut away to the line 22 between the shoulder 20 and 21 to make a clearance for the tooth 19. In making the tongue groove Sand the tongue 17 and, the shoulders 20 and 21, and in lo cating the tooth 19, the key 7 is to be set in the lock 1 so that it will oscillate back and forth to operatethe bolt 23 and so that the key cannot be withdrawn from the lock. In other words, the key 7 is inserted into the key hole 24 and turned until it starts to move the bolt 23 and that is the fixedposition for setting the cylinder 9 so that when the key 16 or-the key 7 is rotated backwardly, the shoulder 21 will strike the tooth 19 before the tongue of the key 7 reaches the slot 2 1 and so that when either key is turned the other way, the should-er 20 will strike the tooth 19 and prevent the key 7 from turning over to the slot 24. At the same time, the parts are set so that the key slot 25 for the key 16. will be in the proper position to withdraw or insert the key, as is usual. The cylinder 9 and key 16 may be of any form or construction which will rotate the connecting plate 15 with the proper key and which cannot be rotated in any other way.

Various changes in the combination and arrangement of parts may be made without departing from the spirit of my invention as claimed.

I claim;

1. The combination with a door, a mortise lock in the door, an escutcheon'plate' on the outdoor side of the door; there being a key hole extending through thedoor and through the mortise lock; and a key inserted through the key hole into the mortise lock from the inagainst the inner face of the escutcheon plate, a key cylinder in the escutcheon cylinspecificationotLetters Patent. P t t .Aug. 27 191 der, a connecting plate rotatably mounted in the inner end of the escutcheon cylinder to rotate with the key cylinder, and a tongue extending from the connecting plate into the groove in the key.

2. The combination with a door, a mortise lock in the door, an escutcheon plate on the outdoor side of the door; therebeinga key hole extending through the door and through the mortise lock; and a key inserted through the key hole into the mortise lock from the indoor side; there being a tongue groove in the inner end of the key; of a safety attachment comprising an escutcheon cylinder mounted in the outer face of the door in line with the key hole,

an attaching flange extending outwardly around the escutcheon cylinder, bolts securing the attaching flange against the inner face of the escutcheon plate, a key cylinder in the escutcheon cylinder, a connecting plate rotatably mounted in the inner end of the escutcheon cylinder to rotate with the key cylinder, and a tongue extending from the connecting plate into the groove in the key; the parts being set so that the key cannot be removed from the mortise look.

In testimony whereofI have signed my name to this specification.

FRED E. KEIZER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

, Washington, D. 0." 

